Fluid pressure operated gun



Aug. 28, 1951k E. R. FITCH FLUID PRESSURE OPERATED GUN Filed Dec. 28, i944 'l BY Patented Aug. 28, 1951v FLUID PRESSURE OPERATED GUN Ellery R. Fitch, Elyria, Ohio, assignor to Bendix- Westinghouse Automotive Air Brake Company, Elyria, Ohio, a corporation of Delaware Application December 28, 1944, Serial No. 570,189

12 Claims.

This invention relates to guns, and more particularly to guns of the type wherein compressed air and other compressed gases are utilized as the propelling force for the projectile of the gun.

It has previously been proposed to utilize compressed air in guns for the above purpose, but many of these guns have required an unnecessary amount of manual effort for compressing the gas, and it is accordingly an object of the present invention to provide means for supplying compressed gas for the operation of the gun so designed as to limit or entirely eliminate this manual eiiort on the part of the operator.

1t has also been proposed to provide a storage reservoir for compressed gas on guns, but in many cases these reservoirs have either been unnecessarily large or of insuicient capacity, and itis a further object of the invention to provide means for storing compressed gas in a gun of the above type, so constituted as to provide a supply of compressed gas sufcient to operate the gun over a long period of time, and at the same time to appreciably reduce the size of the compressed gas reservoir required for this purpose.

Yet another object of the invention is to provide, in connection with a gun of the above type having a storage reservoir charged with gas under pressure, manually operated means controlled by the operator for increasing the pressure of the gas supplied from the reservoir tothe ring chamber.

Still another object of the invention is to provide, in a gun of the above type, means for permitting manual compression of air in the projectile chamber in the event of depletion of the compressed gas in the supply reservoir.

A further object of the invention is to provide novel and eicient means for controlling the ilow of gas from the reservoir to the firing chamber.

Another object of the invention is to provide simple and ecient means for preventing or minimizing leakage of compressed gas from the uid pressure system of the gun.

Yet another object of the invention is to provide a gun of the above type, so constructed as to insure improved accuracy in theflring of the gun by the operator.

These and other novel features and objects of the invention will appear more fully hereinafter from the following detailed description when taken in connection with the accompanying drawing, wherein one form of the present invention is illustrated. It is to be expressly understood, however, that the drawing is utilized for purposes of illustration only, and is not designed as a definition of the limits of the invention, reference being had for this purpose to the appended claims.

In the drawing, wherein similar reference characters refer to similar parts throughout the several views Fig. 1 is a sectional side view of a gun constructed in accordance with the principles of the present invention, and n Fig. 2 is a view of the gun taken from the right end of Fig. l.

Referring more particularly to Fig. 1, the gun is provided with a body portion 4 which may be made of metal or other suitable substance, the body being provided with a handle 5 and a barrel 6 extending longitudinally of the body and arranged in relation to the body and handle as shown. The left portion of the body is provided with a reservoir 1 closed at its lower end by means of a threaded plug 8 and connected at its upper end by means of a conduit 9 to the left end of a cylinder I0 formed in the body. A piston I I, having a packing cup I2 of rubber or other suitable material, is slidably mounted in the cylinder I0, the piston being provided with an operating rod I3 attached thereto and adapted to slide through a bore I4 in the body, and a sealing element I5 being mounted in the bore which acts to prevent leakage to atmosphere from theA left end of the cylinder. The left end of the stem I3 is provided with a head portion IB, and the piston and stem are normally maintained in the position shown by a spring I1 interposed between the right surface of the head I6 and the body.

The handle portion of the body is provided with a bore I8 aligned with the barrel 6 and of substantially the same diameter, this bore being normally closed by means of a plunger I9 provided at its right end with a T-shaped head 20 having an arm 2| adapted in the position shown to engage a notch 22 formed in the handle in order to prevent movement of the plunger to the right. A projectile magazine or bore 23 is formed in the handle as shown, the lower end of the bore being provided with a threaded plug 2i, and the upper end of the bore intersecting the bore I8. When the plug 24 is removed, a plurality of suitable projectiles 25 may be inserted in the magazine 23, the projectiles being forced upward in the magazine by means of a spring 2S interposed between the upper end of plug 24 and the lower surface of a washer 21 slidably mounted in the bore of the magazine. A firing chamber 28 is formed in the body at the right end of the barrel, and in order to prevent leakage from the ring chamber to atmosphere between the bore I8 and the surface of the plunger I9, a seal 29 is mounted in a groove 3l) and is slidably engaged by the outer surface of the plunger. When it is desired to insert a projectile in the right end of the gun barrel, the T handle is turned in a clockwise direction as shown in Fig. 2, the plunger is Withdrawn tOtheYrxight suilici'ently-'jtofpermit a projectile "to enter the bore`l8 at the le'ft of the plunger, and the plunger is then returned to the position shown, a projection 3l formed on the left end of the plunger serving to move a projectile to the position shown at '3'42."`Tl"e "`g`n is now loaded, and it is onlylnecssaryto'supply fluid pressure to the ring'f'lamber intorder'to fire the projectile from the gun.

A valve seat 33 is formedgatlthe upplpdOf this action occurs, a sudden reduction of presjectile leaves the gun barrel, the pressure drops Y rapidly in thechamber 38, and the valve is again 'the'pa'lssag'epreviously described. Means are proin'vd-to`eised position by the action of the spring 36'a 's Wellrasby the action of the Iiuid pressurefsup'pliedvfrom lthe reservoir 'l through Iividedfozautomatipally returning the trigger to the ring chamber 28, and a valve 34 having a piston portion 34-a is` slidably mountedina bore 35 formed in thefbody above and aligned with the rin'g hamberZBthis` valve' vbeing normally maintained in 'closed' position'fby means 'of a spring 36 interposed between thefupper surface of the valve and a'lowerfsurfaceof afplug "31 threadedly received Aby thebody'and Yserving to close the upper end of the bore 35. lAn inlet chamber 38 formedfin?thelow'erfend of the bore below the valve "is connected w'itha firing reservoir 39 formed in the handle 'by means'of a passage', and is"conhected^atfits vupperend to a portion of the bore above the valve :by 'means of a passage 4l liavingav restricted`portion42. The portion of the boreabove the valve forms a control chamber 42L-awliichfisalso connected with the cylinder l0 throughfa'pa'ssage V43, a`valve chamber 44, a passagef provided y'with a choke iBS-a,` a check' valve chamber"46, and av port' 4l, the latter port'being normallyjclose'd by means 'of a check valve'd "urgedaga'inst the right end of the port by means'offaspring 49 mounted in the chamber Ilias-"sl"lovvn,` the left end of the port 41 being connected "witl'iJ` the cylinder I8. ln view of the arrangement of the'cup washer i2 on the f piston Il,l it will be Iunderstood that fluid pressure will be free 'topass 'from'the reservoir l tothe reservoir"39 through vthe passage 9, by the piston cup l2 in thecylinder l0, port 41, check valve 48,valvechanber46,l=passage 45, chamber 44,f"passage"43," b'o're [35, `*passage 4I, chamber 38, and'passa'gelu, the: result being that the small ring reservoir 3Q-'iis'A normally maintained at substantially `the"sainevpressure as the supply 'reservoir- 'l, rtliefonly'f pressure difference being that due to the: restriction-imposed by the piston cup I2"-fa'n`d' theeheck val'vl.

A trigger50 sspivtallyfmounted on the body by means of af'pivo-"pinf'S l ,fthe upper portion' of the trigger at' the* rightfof the-pivotpin 5I being adapted to' engage theilovvefnd-"ofa'valvestem 52 slidably mountedin L'bore 53 V'formed in the body, an exhaust valvefeheadf'lcarried by the upper end'of thestembe'ing' normally maintained in a position'tolclosetheupper'end of the bore by means of'a 'pring' 5.5inte'rposed between the upper end of'the*valveheadfiandthe lower surface of a'plug 56 thieadedlyreceived by the body. The stem"'of' the "valve-'isf lfirovided with flutes 51 which serve,whenthevalveris'moved to open position, toperinitthe flo'W of uid pressure from the valvechamber'44 tov atmosphere through an vatmospheric"port'58- Thus on movement of the trigger' inA a'counter clockwise direction about the'pi'vot pin, the valve 54 is moved to open position' 1ny order toallow iiuid pressure to exhaust from the valve's chamber 44. When 'the position shown'aiter the gun is red in order to'permit closing of valve 54, such means including a port 59 connected at its lower end with thegun barrel` and'atits upper end'with an enlarged bore "55 f; adapted to AVslidably receive a plunger 16 I Athe: lower 'end of the plunger thus being subjected tofthepressure vin the gun'barrel when thev projectile-passes to the Yleft-of the port 5H,v and the upperr end of the plunger'being -in engagement withfai-portion of the trigger Vat the left side-ofthe-pivot=fpin 5|. 'A'suitable seal k62 is 'provided forthe'purpose offpreventing leakage pastA the plunger. T'Since arela-tively lhigh 4pressure is utilized for the yoperation Vofl thegun, the force exerted vby 'thef plunger -is `vsucient to return ithe trigger to the-position shown regardless of the force'exerted thereon by the operator, vand when this occurs, the Valve^54isagain returned to" closed position by the action of thespring 55. As soon as the valve 54 closes, the pressure again increases in the conduit'43;and'thereservoir39 is'again brought lto the sameV pressure as the reservoir 1. Thus the actionof the Valve 34 is controlled by `a sudden change inthe pressure differential acting on 'the 'valve A'which is produced by the operation of the valve 54,'and-no mechanical connection is requiredbetween'the trigger and the valve Y34. Due-to 'the rapid action of the gun, the amount 4of iluid" pressure exhausted through Vthe vport'58 on'o'peration of the trigger is innitesimaL'and `a-verysens`itive control of the firing valve 34 is obtained.

With regard 'to tliefnfieans utilized-for-charging the supply reservoir 1, it has been found'that solid carbon dioxide 'orfDry-Icejwhenfconned in a reservoir, reachesl a 'statebf equilibrium ata relatively high pressure, andj thattherafter the carbon dioxide tends tdchang-e`from-the solid'to the gaseous state to maintain"'thestate of equilibrium whenever gas is removed' from the* reser voir. It is therefore contemplated-that--incharging the gun, the plugr8 may be-remov'ed and' a suitable amount of Vsol-idV carbonCiioiide-inserted in the reservoir 'i to-'substantially fill'the space therein. The plugl 8 isjthen `replacedfirr order to seal the lower end ofthe;reservoirfandthegun is then charged with-an--adequatesupply of gas sufficient to insure 'repeated' firing over? aiv considerable period of time.

Y During normal operationfof fthe gg-un, sufficient pressure will` be maintained inV the -reser- Voir, dueto the chang-e ttheca'rbon ydioxide from its solidied toitsgaseousstate,l to insure an adequate muzzle velocityoi the projectile. In the event it is desired to supply a higher-pressure to the firing reservoir39 in order to increase the muzzle velocity, thef-piston' Il maybefoperated to increase the-'pressure of theegas-'i'n' the as'eaisi cylinder ID, and to this end an operatinghandle 63 is pvotally mounted on the body of the gun by means of a suitable pivot pin 64, a lever arm 65 above the pivot pin being adapted to engage the head IB of the piston rod I3. Thus during this type of operation, the operator may operate the piston for any desired number of strokes to further compress the gas in the cylinder I0, and to deliver it to the reservoir 39 through the check valve 43 and the channels heretofore described, it being understood that during this type of operation the flexible sealing cup I2 on the piston acts as the inlet valve of the pump. In this manner, gas at a higher pressure can be supplied to the reservoir 39 if desired with a relatively small amount of effort on the part of the operator, and muzzle velocities may be obtained if desired which are far in excess of those obtainable in many of the guns of this general type heretofore in common use.

It is also contemplated that it may be desirable t operate the gun in the event of failure of the supply of gaseous carbon dioxide, and this may be readily accomplished by removing the plug 8 from the lower end of the reservoir 1, whereupon the piston l! and the cylinder ID will act solely as a compressed air pump receiving air from atmosphere through the reservoir 'I and the passage 9 and compressing this air in the firing reservoir 39, the pressure obtained in the firing reservoir being in accordance with the number of strokes given to the pump operating lever 63.

As shown in the drawing, the barrel of the gun is preferably so arranged as to lie between the first two i'lngers of the operators hand during operation of the gun, this resulting in a natural pointing of the gun by the operator which is of material assistance in insuring extreme accuracy in firing the gun. While the recoil of guns of this type is relatively small, this positioning of the barrel is such in relation to the position of the hand of the operator as to substantially minimize the eiiect of the recoil force on the aiming of the gun, another factor which contributes to extreme accuracy.

There has thus been provided by the present invention, a nuid pressure operated gun of the repeater type adapted to be operated either by a stored supply of compressed gas or by compressed air, and so constituted as to be capable of carrying a charge of compressed gas suiiicient to insure repeated firing over a considerable period of time, together with a construction which tends to insure extreme accuracy in such iiring. In the event of failure of the supply of stored gas under pressure, means have also been provided for permitting recharging of the gun with compressed air by the operation of a simple pump in the conventional manner, and means have also been provided for permitting the operator to increase the pressure of fluid supplied to the iiring chamber in excess of that obtaining in the supply rescrvoir. A trigger control mechanism for supplying fluid pressure to the firing chamber of the gun has also been provided which is relatively simple and extremely efcient in operation, and which permits a trigger pull of any desired value, the force required to operated the trigger being adjusted when the gun is designed by varying the leverage acting on the stem of the trigger valve d and by varying the area of the valve itself. Simple and efficient means have also been provided for transferring projectiles from the magazine to the ring chamber of the gun,.and

6 for effectively sealing the firing chamber against leakage while the gun is being fired.

Certain features of the invention relating to the magazine and sealing means to prevent loss of pressure when a projectile is fed into firing position from said magazine are described and claimed in my copending application Serial No. 196,596 led November 20, 1950 for Fluid Pressure Operated Gun.

While the invention has been illustrated and described herein with considerable particularity, it is to be clearly understood that the same is not limited to the forms shown, but may receive a variety of mechanical expressions, as will now readily appear to those skilled in the art. Reference will, therefore, be had to the appended laims for a definition of the limits of the invenion.

What is claimed is:

1. The combination in a fluid pressure operated gun having a barrel adapted to receive a projectile at one end thereof, a supply reservoir for storing compressed gas, a firing chamber adjacent said one end of said barrel, and a iiring reservoir, of means for supplying compressed gas from the supply reservoir to the ring reservoir and from the firing reservoir to the firing chamber including a passage between the supply reservoir and firing reservoir, a connection between the firing reservoir and firing chamber, a normally closed firing valve associated with said connection having pressure responsive portions associated therewith subjected respectively to the pressure in said passage and to the pressure in said firing reservoir, and means for controlling the operation of said ring valve, including an exhaust valve operable on movement to open pcsition to reduce the pressure in said passage to a value less than the pressure in said firing reservoir, a trigger for opening said exhaust valve, means for biasing the exhaust valve and trigger toward valve closing position, and means includ-Y ing a movable member responsive to the pressure in the barrel at a point spaced from said one end of said barrel for moving the trigger to valve closing position for permitting closing of the exhaust valve by said biasing means,

2. The combination in a fluid pressure operated gun having a barrel adapted to receive a projectile at one end thereof, a supply reservoir for storing compressed gas, a ring chamber adjacent said one end of said barrel, and a ring reservoir, of means for supplyingcompressed gas from the supply reservoir to the firing reservoir and from the firing reservoir to the ring chamvber including a passage between the supply reservoir and firing reservoir, a connection between the ring reservoir and firing charnber, a normally closed firing valve associated with said connection having pressure responsive portions associated therewith subjected respectively to the pressure in said passage and to the pressure in said firing reservoir, and means for controlling the operation of said iiring valve, including an exhaust valve operable on movement to open position to reduce the pressure in said passage to a Value less than the pressure in said firing reservoir, a pivotally mounted trigger having a part for opening said exhaust valve upon pivotal movement of the trigger to a nring position, means for biasing the exhaust valve and trigger toward valve closing position, and means controlled by the passage of the projectile through the barrel and including a piston member. subjected to thepressure in the barrel and eases; rs1

engaging the f ytrigger*ffora positively moving the latter to valve closing 'position'fforl. permitting closing of the f'exhausti'valveUbyesaid biasingr means.

3. The-combinationeini-a duid/pressure operated gun havingcaebarrelfadapted tov receive2a projectileat one vend-thereof,` a supply reservoir vfor Ystoring compressediigasyaV firing chamber adjacent said one end of said barel,=and a'iring reservoir, of meansfforf supplyingcompressedfgas from the supply reservoir tolthe-firing Yreservoir and from the'ring reservoirfto thelring chamber includingr a'connectionbet'ween thevring reservoir and -vnringchamber, al normally closed control valve, forpreventing theoW-ofcompressed gas from' the-'lringreservoir tothe' lring chamber, pressure :responsive valve Yoperating means associated with the control valve and subjected on one side to the pressure-iin the firing reservoir, a controlchamberf'nf theother side of the pressure responsive means havingrvr afconnection with the viiring 'reservoir-and a-choke infsaid connection, a passage for connecting-said supply reservoir and control chamber, a normally closed exhaust valve positioned in-saidvpa'ssage intermediate said supply'reservoir/and control chamber, a choke in said passage betweensaid exhaust valve and the supply reservoir, said exhaust valve having in openpposition an effective' areagreater than the area of saidlsecond named'fchoke, and means for moving-saidexhaust Valve to open position to exhaust `compressed gas from said passage and to,` reduce ther pressure insaid control chamber to a valuesubstantially-below that in the firing reservoir, whereby the control valve is moved by the 'pressureresponsive means to connect the ring reservoir Vwith the firing chamber.

4. The combination in 'a-luid pressure operated gun havinga Alsaa-rrel-'adapted Vtolreceive a projectile at one end thereof, a supplyl reservoir for storing coinpressedig'aa-faring chamber adjacent said one endofsaidbarrel, and a firing reservoir, of means for supplying compressed gas from the supply reservoirftoI the ringreservoir and from the firing reservoir to theiring chamber including a connection' betweenthe firing reservoir vand firing chamber, aA normally closed control valve, foripreventingvthemo'w. of compressed gas from the ring reservoir V"to the firing chamber, pressure responsive valvev operating means associated with the'v control valveand subjected on one side to the'fpressure in= the `firing reservoir, a control chamber on the-other side of the pressure responsive 'means'havirig--a'con-- nection with the iiring reservoir andi achoke v'in said connection, a passage forconn'ecting-said supply reservoir and con-trol chamber, a normally closed exhaust"valVe-positiond insaid passage intermediate -said-sup`ply reservoir and control chamber, acholefinsaid passage between said exhaust valveand the-supplyreservoir, said exhaust valve having in open positiont'an eiiective area greater than the varea l-ofth'e second named choke, Va trigger for lopeningthe lvalve, means for' biasing the' exhaust valveand 'trigger toward Valve c lo's'igfpositionfand. means operable on ring ofA the-gun for moving the trigger to Yvalve closing.position'ffor` permitting closing of the exhaust valvebythe biasing means-including a pressure responsive fmember having an 'operative connection with' the trigger-1 anda .port in the wallY ofthe barrel for `supplying-conipressedf. gasv to the:` pressure-f` responsive {member from the barreli when' the projectile passessaid port.

f5. In=a iiuid pressure operated gun having-'a Ibarrel adapted to yreceive 4a projectile at one-'end thereof, a ringchamber'adjacent said one end of said barrel, and a supply reservoir forcompressed gas, means for controlling the supply'of compressed gas from the supplyreservoir to the ring chamber including a firing reservoir having a connection with the supply' reservoir and a-connection with ythe firing chamber, said rst connection-including a cylinder connected at one end with a supply reservoir to receive compressed gas from the latter, and connected at the Vother end with the ring reservoir, a` piston in the cylinder, manually operable meansfor reciprocating said piston in the cylinder to increase-the pressure of the gas-in the cylinder vand to deliver -t tothe ring Vreservoir-at the increased pressure, and manually controlled valve means for connecting the firing reservoir With the ring chamber.

6. In a uid pressure operated gun having-a barrel adapted to receivea projectile at one/end thereof,a iiring'chamber adjacent said one end of--said barrel, and a supply reservoir for compressedlgasfmeans for controllingthe supply 'of compressed gas from the supply reservoir to-the firing chamber Aincluding a 4firing reservoir `having aconnection with the supply reservoiradapted to maintain rvthe pressure of gas -in Vthe ringreservoir at Vsubstantially the same value as'the pressurein the supply reservoir, means including a-punip having a cylinder forming apart of said connection to receive a charge ofcompressed gas from the supply reservoir,and having also a--pist0n in thecylinder, manually operable meansto reciprocate-the piston in the cylinder to increase thepressure'of the gas-'in the cylinder and'to supply it to the ring reservoir atthe increased pressure, a-connection between the-firing reser- Voir and firing chamber,y and valve means operable for opening said lastv named connection.

7. In a iiuid pressureoperated gun having a barrel adapted to receive-a projectile at one-end thereof, a ring chamber adjacent said one'end of said barrel, and a supply reservoir for compressed Vgas,V meansl for controlling thevsupply-of compressed gas from the supply reservoir to the firing chamber including a firing reservoir having a connection with the supply reservoir adapted-to maintain the pressure of gas-in the lfiring reservoirl at substantially the-same Value as the pressure in the supply reservoir, means including a pump having a cylinder forming-a part of-said connection to receive a charge of compressed` gas from the supply reservoir, and having also a piston in the cylinder, manually operable-'means to reciprocate the piston inthe c'zylinder'to increase thepr'ssure of theglas in the cylinder'a'nd to s'i'ip'ply'it to the iirin'g'reser- Voir at the increased pressure, a `connectio'n"between thering Vreservoir Vand firing chamber, valve meansoperable for opening said last'named connection, a" fluid pressure actuator for operatingY said 'valvefmeana and means including an operator-controlled valve for lcontrolling lthe supply ofliuid pressure to said actuator.

8. A fluid pressure operated gun having a casing, a supply reservoir `in the casing adapted to be charged with gas under pressure, a barrel positioned'in the casing and vadapted to receive-1a projectile atone end thereof, a firing chamber vin 'the casing'adjacentfsaidv one end of the barrel, a.v A pump',V cylinderv in". the lcasing, Va passage'fconnecting one end of the cylinder with the supply reservoir, a piston slidably mounted in the cylinder adapted to bypass compressed gas from said yone end of the cylinder to the other end thereof and adapted on movement toward said other end to compress gas therein, means for actuating said piston, an outlet passage connected with said other end of said cylinder, a check valve in said passage for preventing the ow of lgas therethrough into the cylinder, an exhaust valve chamber having a normally closed exhaust valve therein adapted on movementto open position to connect said exhaust valve chamber with atmosphere, a trigger for operating said valve, a restricted passage for connecting said outlet passage and exhaust valve chamber, a firing reservoir, a control valve bore, a control valve slidably mounted in the bore having a piston portion dividing the bore into a control chamber and an inlet chamber, a connection between the ring reservoir and inlet chamber, a port in said inlet chamber having a connection with the ring chamber, resilient means for normally maintaining the valve in port closing position, a supply port in the wall of the control chamber bore having a connection with the exhaust valve chamber, and a passage of restricted area connecting said control chamber and inlet chamber for supplying compressed gas to the inlet chamber and ring reservoir, the combined area of said last named passage and the restricted passage between said outlet passage and exhaust valve chamber being less than the effective area of the exhaust valve when moved to open position by the operation of the trigger, whereby on opening of the exhaust valve the pressure in said control chamber is rapidly reduced and the pressure in the inlet chamber acting on the-piston portion of the valve moves the latter to open the inlet chamber port to connect the tiring reservoir with said firing chamber.

9. A uid pressure operated gun having a casing, a supply reservoir in the casing adapted to be charged with gas under pressure, a barrel positioned in the casing and adapted to receive a projectile at one end thereof, a firing chamber in the casing adjacent said one end of the barrel, a pump cylinder in the casing, a passage connecting one end of the cylinder with the supply reservoir, a piston slidably mounted in the cylinder adapted to bypass compressed gas from said one end of the cylinder to the other end thereof and adapted on movement toward said other end to compress gas therein, means for actuating said piston, an outlet passage connected with said other end of said cylinder, a check valve in said passage for preventing the flow of gas therethrough into the cylinder, an exhaust valve chamber having a normally closed exhaust valve therein adapted on movement to open position to connect said exhaust valve chamber with atmosphere, a trigger for operating said valve, a restricted passage for connecting said outlet passage and exhaust valve chamber, a firing reservoir, a control valve bore, a control valve slidably mounted in the bore having a piston portion dividing the bore into a control chamber and an inlet chamber, a connection between the -firing reservoir and inlet chamber, a port in said inlet chamber having a connection with the ring chamber, resilient means for normally maintaining the valve in port closing position, a supply port in the wall of the control chamber bore having a connection with the exhaust valve chamber, a passage of restricted area connecting said control chamber and inlet chamber for supplying compressed gas to the inlet chamber and firing reservoir, the combined area of said last named `passage and the restricted passage between said outlet passage and exhaust valve chamber being less than the eiective area of said exhaust valve when moved to open position by the operation of the trigger, whereby on opening of the exhaust valve the pressure in said control chamber is suddenly reduced and the pressure in the inlet chamber acting on the piston portion of the valve moves the latter to open the inlet chamber port to connect the firing reservoir with the iring chamber and re the projectile through the barrel, and means controlled by the passage of the projectile through the barrel for moving the trigger to exhaust valve closing position including a cylinder, a piston mounted therein having an operative connection with the trigger, and a port in the wall of the barrel connecting the last named cylinder with the barrel at a point spaced from said one end thereof, whereby compressed gas is supplied from the barrel to said last named cylinder when the projectile passes said last named port.

10. In a fluid pressure operated gun having a barrel adapted to receive a projectile at onek end thereof, a ring chamber adjacent said one end of the barrel, and a supply reservoir for compressed gas, means for controlling the supply of compressed gas from the supply reservoir to the ring chamber including a firing reservoir having a connection with the supply reservoir adapted to maintain the pressure of gas in the ring reservoir at substantially the same value as the pressure in the supply reservoir, means including a pump having a cylinder forming a part of said connection to receive a charge of compressed gas from the supply reservoir, and having also a piston in the cylinder, manually operable means to reciprocate the piston in the cylinder to increase the pressure of the gas in the cylinder and to supply it to the firing reservoir at the increased pressure, a connection between. the firing reservoir and firing chamber, a fluid pressure responsive valve associated with said last named connection, resilient means normally urging said valve to a position to close said last named connection, and means for controlling the supply of compressed gas to said valve to open the latter against the action of the resilient means, comprising an operator-controlled valve for reducing the pressure of the gas in the iirst named connection.

11. In a fluid pressure operated gun having a barrel adapted to receive a, projectile at one end thereof, a firing chamber adjacent said one end of the barrel, and a supply reservoir for compressed gas, means for controlling the supply of compressed gas from the supply reservoir to the ring chamber including a firing reservoir having a connection with the supply reservoir adapted to maintain the pressure of gas in the firing reservoir at substantially the same value as the pressure in the supply reservoir, means including a pump having a cylinder forming a part of said connection to receive a charge of compressed gas from the supply reservoir, and having also a piston in the cylinder, manually operable means to reciprocate the piston in the cylinder to increase the pressure of the gas in the cylinder and to supply it to the ring reservoir at the increased pressure, a connection between the firing reservoir and firing chamber, a uid pressure responsive valve associated with :aga-665181 said: lastxnamed connectionl and positioned to normallyclose :said last named'. connection, said valve' having; pressure responsive. portions subjectedirespectivelyfto'thezpressure -of th'e gas in thee-rst'named' connection and' to the pressure ofstliefgas in the firingreservoir, and'means for controlling; the supply of compressed gas to said valve:` tonopen the'latter, .comprising a normally closed: exhaust'z valve, positioned in said rst named'connection'between said cylinder and said valve-,'andf'operatore-controlled means for opening saidexhaustzvalvezto'reduce the'pressure of the gas-:inv thez-rstinamedf'oonnection to a'valuelless than thefpressure inA said nring` reservoir.

12,:,In' a fluid'. pressure operated gunv having.v a barrel-,adapted to receive `a projectile' at'one end thereof;,awringxchamber adjacent saidone end of:- the barrel, and=a supply reservoir for cornpressedgasg, means for controlling the supply of compressed gas frornzthe supply reservoir to the rmgfchamber'including a ring reservoir havinga connection With'zthe supply reservoir adapted ,tomaintain theeipressure of gas in the'ring reservoir atzsubstantially,thewsame value: as the pressurein the supplyreservoir, means-including 'al-:pump having a'cylindergforming 'a part of said connectionzto; receive a?v charge of compressed 'gas from the supply'reseryoir', and having also. apistonrin the cylinder; manually operable means to reciprocateg-the pistonpimthe cylinder to increase the pressurenof; the gasf: in the3cylinder andv to supplygv-ittonthe;firing lreservoir at'ithe increased vpressure,A a lconnection between' the ',ring reservoir and;ring chamber-,1a fiuid'pressure respon-V sive: valve associated iwith said' last 'named con-V nection and-positioned to normally close'said last named connection, said :valve having; pressurefree sponsive,- portions subjected respectively to the pressureofithe'gas inthe first named connection4 and to Ythe-,pressure of the gas in the ring' reservoir, and said rstnamedconnectioninclud'- ing arestrictedbyepass aroundsad valve, andl means forcontrollingthesupplyof compressed gas `to.sr 1fidvalveto open the latter, comprisinga-norma'lly-l closed exhaustV valve positioned in sa-id-firstnamedA connection between said cylinder andsaid-valveand operable on movement toopenrposition to reduce the pressure of the Number Name Date'- 294,352.V Bartlett` Mar. 4, 1884 353,430 Reynolds Nov. 30',- 1886 421,306,` Reynolds Feb. 11,' 1890' 421,308v Reynolds Feb. l1, 1890 430,101V Zalinski June'lO, 1890 441,676- Lovegrove Dec. 2,' 1890 452,882 Griiard'V May 26, 1891 597,588v Nygren- Jan. 18', 1898 605,841Y Bates; June 21,I 1898 670,760 Bennett Mar'. 2S, 19,01 756,182 Novakf, Mar. 29, 1904 876,370 Markham etal.v ,Janz 14,' 1908' 1,073,312y Woods Sept; 16, 19:13 1,214,398 Welch Jan. 3 0, 1917' 1,240,989 Lefeveri Sept. 25,' 1917 1,404,689 Fairweather' Jan: 24,` 1922 1,486,215 Zerbee Mar.A l1, 1924' 2,061,341 Aigner ,Nov. 17, 1936 2,119,441 Pricef- May 31, 1938v 2,182,369 Barron Dec. 5, 1939' 2,238,384 Feltman Apr. 15, 1941 40 2,296,834 Boynton Sept. 29, 1942- 2,304,841 Mikkelsen Dec. 15,' 1942 2,375,314 Mills May 8, 1945 FOREIGN PATENTS Number, Country. Date 444,508 France Oct. 19, 1912 334,644 Germany Mar. 18, 1921 gasjn saidrst namedV passage to a' value'lless than-the. pressure in said ring reservoir, a triggerf for opening said exhaust valve, means for biasing the exhaust valve and triggerV toward valve' closing position, and means including a movable member responsive to the pressure in the barrel at a point spaced from said one end of .rtheibarrelfor moving the trigger to'valve closingzposition for permitting. closing of the exhaust valve by :said biasing means.

ELLERY R. FITCH.

REFERENCES CITED.

Thefollowlng references'are'of record in the le'of 1this patent: y

UNITED. STATES PATENTS 

